Three new siphonostomatoid copepods are associated with Ophiuroidea in the tropical western Atlantic. Collocheres vervoorti spec. nov., from Ophiothrix angulata in Jamaica, has an elongate, gently tapered genital double-somite in the female and the second segment of leg 5 has a distal outer notch.Collocheres lunulifer spec. nov., an associate of Ophiothrix angulata and Ophiothrix suensonii in Barbados, has sclerotized lunules on the basis and first segment of the endopod of leg 1. Ophiurocheres bellulus gen. nov., spec, nov., living on Ophiomyxa flaccida in Puerto Rico, has the third segment of the exopod of leg 1 armed with 11,2,2 and the second segment of leg 5 bears 2 setae in the female and 3 setae in the male.